The present invention relates to a balancing board, and more particularly to a roller and treadle board device in which the board rests on and is releasably interconnected to the roller for safe and convenient exercise and amusement purposes.
Rudimentary seesaws or rockers are known, but there is no relative linear movement between their elements.
Specifically, U.S. Pat. No. 253,571 to Adams, and U.S. Pat. No. 1,865,612 to Bustillos, show collapsible seesaws in which angular side members are fixedly hingedly interconnected with a flat stationary fulcrum base to form a one piece triangular unit which can be folded for storage.
Also, U.S. Pat. No. 357,577 to Cashin shows a pair of hinged side arms removably mounted in a central rocker to form a seesaw, while U.S. Pat. No. 2,198,947 to Olson shows a collapsible seesaw in which a flat, lockable multiple section board is pivoted on a fulcrum base, yet when unlocked the board is foldable on itself in hinged sections, although it remains fixedly pivotally connected to the base.
U.S. Pat. No. 3,833,215 to Isdith shows a balancer device in which a roller is fixedly pivotally connected to a U-shaped cross bar on which a user may stand to operate the device, there being no relative movement between the roller and cross bar, such that the device performs as a kind of rolling seesaw.
On the other hand, balancing boards are also known, in which there is relative movement between the elements.
Thus, U.S. Pat. No. 2,764,411 to Washburn, Jr. shows a roller having a circumferential groove and a board containing a longitudinal track on its underside which fits in the groove for effecting the usual relative longitudinal movement between the roller and board and rocking movement of the board on the roller, the track having end stops to keep the board from rolling off the roller. However, there is no interconnection between these two separate elements.
U.S. Pat. No. 3,488,049 to Sasser, Jr., and U.S. Pat. No. 3,895,794 to England, show similar two element arrangements in which the roller merely rides in a flat or arched longitudinal recess in the underside of the board, the ends of the recess acting as stops to keep the board from rolling off the roller, but the two separate elements are not interconnected.
U.S. Pat. No. 2,829,891 to Ludwig shows a roller having a circumferential groove and a board containing a longitudinal hollow track on its underside which fits in the groove for effecting the usual relative longitudinal movement between the roller and board and rocking movement of the board on the roller, a rope being wound around the roller groove and disposed along the hollow track such that its ends are hand held by the user standing on the board to control movement and keep the board from rolling off the roller. However, there is no mechanical interconnection between the separate board and roller.
U.S. Pat. No. 4,601,469 to Sasser, Jr. shows a hollow roller and a board containing a longitudinal recess on its underside in which the roller is received, the recess end walls acting as stops preventing the board from rolling off the roller, and the recess side walls having parallel channels for receiving the ends of a straight pin or cranked and flexible pin passing through the hollow roller to connect the roller to the board.
In the case of the Sasser, Jr. straight pin, this connection is more or less permanent, since the roller ends and pin ends must closely abut the recess side walls and blind inner ends of the channels, respectively, to prevent sidewise wobble and yaw of the board relative to the roller during use, such that a special opening in one recess side wall and leading to its channel must be used to insert the straight pin via that channel through the hollow roller until it is seated in the opposite channel. Once inserted, it is difficult and time consuming to realign the pin with the opening, given the confined space involved, for removal to separate the three elements, and once separated they are apt to go astray.
In the case of the Sasser, Jr. cranked end flexible pin, such an opening cannot be used to assemble the three elements. Instead, the pin must be flexible so that after inserted in the hollow roller it may be bended to distort its ends into the side wall channels. However, the roller is shown to be shorter than the recess width, apparently to provide room for such manipulation, given the confined space involved, such that the roller ends do not closely abut the recess side walls, and thus cannot prevent sidewise wobble and yaw of the board relative to the roller during use. Here also, once inserted, it is difficult and time consuming to bend the pin in such confined space for release to separate the three elements, and once separated they are apt to go astray.
U.S. Pat. No. 3,630,540 to Smith shows a roller having a circumferential groove and a board containing, inter alia, a longitudinal flexible coil spring or rod on its underside which is interconnected with the roller at its groove. In the case of the spring, a longitudinal track fits in the roller groove to keep the roller in proper alignment with the board, and the spring ends are permanently attached to the board while its middle span extends around the groove underside to provide a temporary interconnection only to the extend that its positive tension prevents the roller from becoming detached. However, the spring is subject to constant wear since the groove rubs against its middle span continuously during use.
In the case of the Smith longitudinal flexible rod, its ends are also permanently attached to the board while its middle span is journalled in a bore in a bracket rotatably mounted on the roller, so as to provide a permanent interconnection with the roller. However, there is no longitudinal track to fit in the roller groove to keep the elements in proper alignment during use, as with the spring arrangement. Hence, the roller is subject to sidewise wobble and yaw as the board moves relative thereto, since the rod is flexible, and this will in turn subject the journal interconnection between its middle span and the bracket bore to constant sliding stress and twisting in all directions as well as to high wear.
It would be desirable to provide a balancing board device of the above type, composed of only two relatively movable elements, which are interconnnected for use without sidewise wobble or yaw or fear of undesired separation, yet which may be readily separated for self-contained transport or storage.